The present invention relates to an emergency informing system including an emergency informing terminal mounted on a vehicle or other mobile body for communicating with the center supervising emergency informing system in case of emergency, and the emergency call center supervising the emergency informing system for receiving an emergency call send signal from this emergency informing terminal. More specifically, it relates to a system having a countermeasure function against abnormality such as failure of emergency informing terminal.
The invention further relates to a system designed to cut off power supply to the emergency informing terminal by judging abnormality, in particular, when the supply voltage of the auxiliary battery drops or a current flows more than specified in the emergency informing terminal.
Hitherto, an emergency informing terminal is mounted on an automobile or other vehicle, and is used in communication with the center supervising the emergency informing system such as the police or emergency call center, through a base station of communications operator or the like, in case of emergency such as traffic accident or sickness while driving.
FIG. 17 is a block diagram of a transmitter of a conventional emergency informing system disclosed in Japanese Laid-open Patent No. 9-198592, and its operation is explained below. As shown in FIG. 17, the transmitter 70 of this emergency informing system comprises GPS receiving means 71, main control means 72, emergency call notifying means 73, input, display and talk means 74, memory means 75, failure detecting means 76, and a power source 77, and they are mutually connected through data bus 700. The GPS receiving means 71 receives position information and other data through a GPS data link 701. The main control means 72 periodically reads out reception data from the GPS receiving means 71, calculates time data and position data, and stores in the memory means 75. The main control means 72 controls the entire transmitter 70. The emergency call notifying means 73 controls a call to connect the transmitter 70 to a wireless public telephone line 702, and the input, display and talk means 74 enters and displays the telephone number of the partner, talks with the partner, and enters the control information to the transmitter 70. The failure detecting means 76 detects abnormality when, for example, impact, heat or rotation is applied to the automobile or other mobile body on which the transmitter 70 is mounted, and notifies this abnormality to the main control means 72. The power source 77 receives supply of main power source from the mobile body, and feeds its power to individual means. The power source 77 also functions as a backup power source for the transmitter 70 in case the main power source of the mobile body is cut off.
In the configuration of this conventional transmitter 70, the GPS receiving means 71 receives position information through the GPS data link 701, and the main control means 72 periodically reads out reception data from the GPS receiving means 71, calculates time data and position data on the basis of the position information, and updates the content of the memory means 75 by the latest time data and position data obtained by the calculation. On the other hand, the failure detecting means 76 is always monitoring for abnormality due to impact, heat, rotation or the like in the automobile or other mobile body on which the transmitter 70 is mounted, and when detecting abnormality, it notifies to the main control means 72. Receiving the notice of detection of abnormality from the failure detecting means 76, the main control means 72 control the emergency call notifying means 73, and connects the dialing line to the center for supervising the emergency informing system, and transmits the failure occurrence message created by including the latest time data and position data stored in the memory means 75 to the center. As a result, if communication from the driver to outside is disabled due to accident of the mobile body or the like, occurrence of abnormality of the mobile body can be promptly transmitted, together with the position information, to outside.
On the other hand, the technology for enhancing the safety of the vehicle by enhancing the reliability of the automobile or other vehicle is disclosed, for example, in Japanese Laid-open Patent No. 9-151780. In the electronic control unit (ECU) such as engine control unit in which control objects in the vehicle are distributed by function, a microcomputer may be used for electronic control. When composing the control system by using microcomputer, all controls may not be always done by one microcomputer only, but control processes may be divided into plural groups, and one microcomputer is assigned for one process, and the data of other microcomputer necessary in each microcomputer is obtained through a communication path which connects all microcomputers, which is known as multi-microcomputer system. FIG. 18 is a block diagram showing an example of configuration of such multi-microcomputer system, in which an electronic control unit 90 is composed of two microcomputers, that is, a first microcomputer 91 and a second microcomputer 92 connected through a communication path 93, and a first control object 94 and a second control object 95 are controlled. In such constitution, while mutual microcomputers exchanged data, the microcomputers monitor abnormality of each other through the communication path 93, and the reliability of electronic control unit is enhanced, and the reliability of the vehicle itself is enhanced.
Thus, to enhance the safety of the automobile, while enhancing the reliability of the vehicle itself, it is simultaneously attempted to improve the emergency informing system for informing an emergency case of the automobile to the center for supervising the emergency informing system promptly from the emergency informing terminal.
However, in the transmitter of the conventional emergency informing system shown in FIG. 17, in case of emergency such as accident of the automobile itself or sickness, the occurrence of abnormality is notified to the center by the emergency informing system by the driver or by failure detecting means. Further, by the main control means for controlling the entire transmitter, the operation is managed including the abnormality of the transmitter itself. In the event of trouble or abnormality of the main control means, however, the main control means itself is abnormal, and the abnormality cannot be noticed to the user, and the abnormal state is left as it is, and further since the abnormality history cannot be recorded, it is difficult to identify the cause of abnormality.
Meanwhile, in the multi-microcomputer system as shown in FIG. 18 intended to enhance the safety and reliability of the vehicle itself as in the conventional automobile mentioned above, as means against trouble of control unit of engine or the like in the vehicle, two microcomputers usually controlling the control objects monitor mutually for abnormality, and if one becomes abnormal, its abnormality is detected by the other to notify the driver promptly. Thus, in the vehicle in which the safety is very important, the reliability of the vehicle itself is enhanced, but it has not been sufficient for enhancing the reliability of the emergency informing terminal itself as the means for informing outside of abnormality such as emergency case of accident or sickness in the mobile body. That is, in the transmitter of the conventional emergency informing system, if the main control means becomes abnormal, the user does not know the abnormality at this moment, but recognizes the abnormality only when the emergency informing system fails to operate at the moment of emergency, and it is inconvenient because the emergency informing system cannot be used in case of emergency.
Further, in the conventional emergency informing terminal, the operation is realized by the power supply from the existing main battery in the vehicle, and if the main battery is broken due to traffic accident or the like and power supply from the main battery is interrupted, the operation is realized by changing over to the power supply from the auxiliary battery incorporated in the emergency informing terminal.
The power supply from the auxiliary battery is controlled by the power control device provided in the conventional emergency informing terminal, and this power control device monitors the supply voltage of the main battery, and when detecting voltage drop, it is controlled to change over to power supply from the auxiliary battery. Further, the power control device monitors the supply voltage of the auxiliary battery, and when the voltage of the auxiliary battery is lowered below a prescribed value, the abnormality of the auxiliary battery is noticed to the user.
In the conventional emergency informing terminal, however, in the auxiliary battery, in case of abnormality such as short circuit of supply source and GND, only the abnormality is noticed to the user due to voltage drop, and the problem of heat generation by such short circuit is not solved. If the auxiliary battery is short-circuited, there was a problem of damage on the emergency informing terminal due to heat generation.
The invention is devised in the light of such conventional problems, and the emergency informing terminal of the invention mounted on a vehicle or other mobile body, for making an emergency call notifying process by radio communication to the center for supervising the emergency informing system comprises a main controller for controlling the emergency informing terminal, and a sub controller for controlling communication with an external device mounted on the mobile body.
In the emergency informing terminal, the main controller monitors the operation of the sub controller, and the sub controller monitors the operation of the main controller.
In such constitution, the main controller and sub controller usually controlling the individual control objects can monitor mutually for abnormal operation each other while controlling as usual, and if one fails, the other can detect its abnormality, and the abnormality can be notified to the user, and history of abnormality can be recorded.
Further, the emergency informing terminal of the invention is an emergency informing terminal mounted on a vehicle, and capable of continuing the emergency call notifying process securely by changing over the power supply from the main battery of the mobile body to the power supply from the auxiliary battery, and the auxiliary battery comprises means for cutting off power supply to the emergency informing terminal if abnormality occurs in the power source.